public class Fu{
    //私有成员属性
    private int f;
    protected int f1;
    public int f2;
    int f3;
    
    //构造器 无参构造器
    public Fu(){
        System.out.println("父类无参构造器");
    }
    //全参构造器
    public Fu(int f){
        this.f = f;
        System.out.println("父类全参构造器");

    }
}